25 March, 2025CAT 3126B Fault Code: 91-08 PID: Flash Code 32 SPN: FMI: Invalid Throttle Signal The Speed/Timing signal or Engine Speed/Timing Sensor #2 is lost and then returns (intermittent). Share on Facebook Opens in a new window. Tweet on Twitter Opens in a new window. Pin on Pinterest Opens in a new window. Back to blog Leave a comment Name * Email * Comment * Please note, comments need to be approved before they are published.